Hi all,
I am investigating the GIC Stream protocol and having a confusing issue as the title.
The figure below shows the case that an interrupt is retrieved from CPU interface.
As explained in the GIC Stream Specification, there may be 2 reasons:
1. The relevant group enable in GICD_CTLR is cleared by software (I can understand it).
2. The pending interrupt is configured to use the 1-of-N model, and the IRI selects a different target PE.
For the second reason, because an interrupt (SPI) is sent to a target PE only, instead of being broadcasted to all PEs that share the interrupt,
only the redistributor that connects to the PE should send the Set x Command to CPU interface. Therefore, this reason seems unreasonable as my understanding.
Anyone can make this explanation clear?
Thank you.